Vernonia oil is an inedible oil which may be derived from various different plants classified within genus vernonia in the family asteraceae (Compositea). There are over 1000 different species in genus Vernonia with numerous different varieties, in the form of trees, bushes or flowering weeds. Various varieties and parts of the plants have been used in folk medicine around the world. The properties of a particular variety do not appear to be exhibited by all of the vernonia plants and it has been found that each variety must be individually evaluated as to its particular uses or benefits. Most of the applications are based on ingestion of extracts, teas or whole or powdered parts (leaves, bark, roots) of the tree, bush or weed. These applications include a broad range of intestinal or gastric problems (stomach ache, cramps, digestive aid, appetite stimulant, nausea, diuretic, laxative, ulcers, purgative, gastritis, enteritis, colic, dysentery) venereal diseases or genital problems (gonorrhea, impotence, metrorrhagia, regulate menses, labor pain, reproductive problems, relief, abortifacient, aphrodisiac, lactogogue) infection, convulsions and spasms, common cold, pneumonia, cough, fever, malaria, bleeding, hemorrhage, epistaxis, anemia, diabetes, kidney problems and metabolic diseases associated with the liver, ringworm, vermifuge, cholera, scurvy, yaws, mange, sprue, snake bite, asthma, headache, night blindness and for certain varieties as a topical treatment for the skin, sores and wounds (V. arborea, V. amygdalina, V. kotshyana, V. missurica, V. Sp, V. teres). It has also been reported that vernonia anthelminticum contains a chemical that may be effective in treating psoriasis. However, the fact that a particular variety has been suggested in folk medicine for a particular condition does not mean that it is in fact effective for the identified malady, will provide a clinically effective result, or that other plants in the genus vernonia will demonstrate the asserted function.
V. galamensis (some times referred as V. pauciflora) is an annual plant ranging in plant height from 0.2 m to 5.0 m depending on the subspecies and the geographic location. Two centers of diversity are Kenya and northern Tanzania with only one botanical variety occurring outside eastern Africa. V. galamensis differs from other annual species of Vernonia in leaf form, and/or pappus, and involucre form and size. The seed head (capitula) contains hermaphroditic, protandrous florets.
Oil can be extracted from the seeds of V. galamensis using hexane and the fatty acids and glycerides can then be removed from the hexane using a solid phase extraction procedure. An aminopropyl phase has been used for the extraction to retain analytes from the non-polar matrix through interactions between the amino groups on the modified silica surface and the carbonyl groups on the fatty acids and glycerides. For the elution step, advantage is taken of the differences in the lipophilic character between the fatty acids and the glycerides by eluting each of these fractions with solvents of different polarity.
Like other vegetable oils, vernonia oil is a mixture of glycerides, mainly triglycerides, a combination of three fatty acids esterified to a glycerol molecule. The principal fatty acid in vernonia oil is vernolic acid, a naturally occurring epoxidised fatty acid. Two species have been primarily identified as a source of epoxidized oils for various different industrial applications, Vernonia Galamensis and Vernonia Anthelminticum. The vernolic acid in vernonia oil recovered from these species is a commercially important epoxy fatty acid because it is easily polymerized. It is useful for metal coatings, and as a diluent for alkyd paints, in plasticizers, adhesives, synthetic fibers and plastics. The vernonia oil is of a higher quality then epoxidized linseed and soybean oils that are currently used for these applications.
WO 02/055011, published in the U.S. on Jun. 2, 2005 as U.S. 2005/0118248 describes the use of amphiphilic derivatives having at least one fatty acid chain derived from vegetable oils, such as vernonia oil, in the production of vesicles, micelles and complexants. WO 03/047499 describes the use of ampiphilic compounds to form vesicles or liposomes for use in drug targeting. The particular source of vernonia oil was not indicated and Vernonia Galamensis as a source is not mentioned. Also, no mention was made in these publications of the medicinal benefits of vernonia oil, the application described being the formation of vesicles to carry other medicinal compounds.
U.S. Pat. No. 6,680,391, to Raman et al, as well as other patents by the same inventors, mentions that preparations from vernonia anthelminticum has been used in folk medicine for the treatment of vertiligo. Several patents issued to Deckers et al, of which U.S. Pat. No. 6,599,513 is one example, are directed to topical emulsions in which oil from Vernonia Galamensis is listed, along with many other plant sources of oils, for forming the emulsions. While these emulsion are said to be usable in personal care and dermatological products there is no mention of any particular therapeutic benefits, the oils merely serving as carriers for other materials. Numerous other patents also mention vernonia oil, along with other plant derived oils as ingredients in various compositions or as a reactant in industrial products. Again, no therapeutic benefits are suggested.
The seeds of both Vernonia anthelminticum and Vernonia galamensis are about 40% oil. EP-A-1198237 discloses the use of extracts derived from the seeds of Centratherum anthelminticum (also known as Vernonia anthelmintica) for the treatment of skin disorders, such as impetigo and acne, and fungal infections of the skin and nails. U.S. Pat. No. 5,693,327 discloses the use of compositions containing extracts of Centratherum anthelminticum, which compositions may be in a form suitable for topical application, for the treatment of psoriasis, eczema and lichen planus. Oil derived from Centratherum anthelminticum seed is known to contain significantly less vernolic acid than Vernonia Oil (Teymor et al. “Vernonia”, Alternative Field Crops Manual, updated 26 Jan. 2000, discloses the vernolic acid content of oil derived from Vernonia galamensis seed to be about 30% more than the best varieties of Vernonia anthelmintica). A typical analysis of the oil is 79-81% vernolic acid, 11-12% linoleic acid, 4-6% oleic acid, 2-3% stearic acid and 2-4% palmitic acid (Ayorinde, F. O. et al. “Vernonia Galamensis: A Rich Source of Epoxy Acids”, J. Amer. Oil Chem. Soc., 67, p 844 (1990). However, according to the literature these species are very difficult to harvest because the seed pods tend to shatter and scatter the seeds before they can be collected. On the other hand, the leaves of Vernonia galamensis have 0.5% or less of vernolic acid.